In a typical network environment, multiple client computer systems (clients) are connected to one or more server computer systems (servers). In a first common arrangement, each client system includes an operating system, and optionally other software, stored on a mass storage device such as a hard disk drive within the client. On power-up or reboot, the client boots from the hard disk drive without reference to the server computer (`local boot`). Other application software e.g. word processing, database software etc, which may be held on local storage or on remote storage associated with the server, is accessed as needed by the client.
In an alternative network configuration, the client computer is required to boot from the server (so-called remote boot). The client may or may not include a mass storage device such as a hard disk drive. In the latter case, the client is reliant on the server to provide operating system and other software. Consequently, when such a client system is powered-up or rebooted, the client fetches its operating system software from the server system and stores the software in volatile memory for use until the client system is powered-off.
A network of the remote-boot type in which each client system boots from a remote server system has an advantage over the `local boot` network in that the network administrator has full control over the software downloaded to the client for storage in volatile memory. In this manner, the network administrator is able to control the operation and configuration of all the client systems with one consequence that the client users can be prevented from installing and using undesirable and/or unlicensed software on their client systems. Furthermore, in this type of network, the overall equipment costs are reduced by the cost of a hard disk drive for each client. The overall network operating costs are thus typically seen to be lower than the costs of a local boot network.
However, a remote-boot network has a number of disadvantages, not the least of which is high network loading caused when a large number of clients attempt to boot at approximately the same time, as would happen for example at the start of the working day. This overloading causes general disruption and reduced efficiency (especially in large network environments) and more particularly results in a delay in the loading of software images to the client systems thereby delaying the time from which the client systems become operational.
One way in which this problem can be reduced is to provide a higher ratio of server to client systems. However, an increase in ratio would raise the overall equipment costs of the network thus largely negating the lower maintenance costs. Alternatively, the network could make use of broadcast protocols to transmit the same download information to all the clients. This technique would still require several minutes to boot the client computers and depends on all the clients requiring the same download software image, thus greatly reducing flexibility.
In view of the above, it would be a desirable objective to provide the means by which network loading can be reduced in a remote-boot network.